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Super‐High Strength Mg–7.5Al–0.8Zn Alloy Prepared by Rapidly Solidified Powder Metallurgy and Low Temperature Extrusion
Author(s) -
Zhu Jian,
Liu Junxiu,
Wang Yi,
Lu Kuang,
Chen Jinbin,
Liu Zikui,
Hui Xidong
Publication year - 2018
Publication title -
advanced engineering materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.938
H-Index - 114
eISSN - 1527-2648
pISSN - 1438-1656
DOI - 10.1002/adem.201700712
Subject(s) - extrusion , materials science , ultimate tensile strength , alloy , powder metallurgy , indentation hardness , nucleation , grain size , metallurgy , phase (matter) , nanoscopic scale , composite material , microstructure , nanotechnology , chemistry , organic chemistry
In this work, Mg–7.5Al–0.8Zn alloy with super‐high tensile strength are fabricated by rapidly solidified powder metallurgy (RS/PM) and low temperature extrusion technology. By reducing extrusion temperature from 340 to 170 °C, the α ‐Mg grains are significantly refined and numerous nanoscale β ‐Mg 17 Al 12 particles are obtained. The RS/PM alloy extruded at 170 °C possesses the lowest grain size of ≈550 nm. The nanoscale β ‐phase particles stimulate the nucleation of dynamically recrystallized (DRXed) grains and restrain the growth of DRXed grains. The RS/PM alloy extruded at 170 °C exhibits mechanical properties with a tensile yield strength of 448 MPa, an ultimate tensile strength of 480 Mpa, and a microhardness of 137 HV. These excellent mechanical properties result from low temperature extrusion are mainly attributed to the ultra‐fine DRXed grains and the high‐density dislocations and subgrains.